Operators perform manual testing and verification of a radio network by doing drive testing with specific measurement tools to collect data in order to verify the network deployment and operation. The third generation partnership project, 3GPP, is working on standardized solution to substitute manual testing by specifying features that would enable usage of commercial devices to support network verification and optimization by providing appropriate measurement reports for minimization of drive tests, MDT, purposes. Identified use cases are e.g. optimizations of network coverage, capacity, or mobility parameters, etc. These measurement reports could help operators to reduce manual testing of the network and therefore to lower the operational costs.
Two different modes have been defined for the MDT measurements, namely immediate MDT and logged MDT. Immediate MDT applies normal radio resource control, RRC, measurement configuration and reporting principles except the extension to request and report user equipment, UE, location as part of the measurement data. The reporting may be triggered by a separate “event” which may be the same events that are used for radio resource management, RRM, reporting. UE makes MDT measurements and immediate reporting when the UE is in radio resource control, RRC, connected mode. Logged MDT enables idle mode measurement results to be logged together with time and location information. The log may be reported at later stage when the connection has been set up again.